Plasma spray formed near-net-shape MoSi2-Si3N4 bulk nanocomposites-structure property evaluation

This article, for the first time, presents the challenges toward the successful consolidation of near-net-shape bulk MoSi2-Si3N4-SiC nanocomposite using plasma spray forming. A detailed characterization of the spray formed bulk nanocomponent has been performed using optical microscopy (OM), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), and Vickers hardness testing. Vickers hardness (900 Hv) and fracture toughness (∼>5 MPa m1/2) of the nanocomposite showed a little deviation from the expected, which might be due to the difference in the particle (Si3N4) size and their distribution in the MoSi2 matrix as a function of component thickness. Relatively higher hardness is attributed to the retention of the nanostructure in the composite. In addition, the as fabricated bulk nanocomposite showed enhanced oxidation resistance.